Collaborative Research: geophysical evaluation of biogenic gases in peatlands

来自北部泥炭地的生物气体排放，通过维管植物的抽吸和周期沸腾事件，约占全球每年向大气排放的甲烷的7%。该提案包括应用探地雷达（GPR）进行以下实验：(1)估算泥炭地储存的生物气量；(2)确定泥炭内生物气的空间分布；(3)监测生物气释放到大气中的情况。来自缅因州北部大型泥炭地（EAR-0242353）的数据表明：(1)较高的CH4和CO2浓度与井间探地雷达数据中的高速度/高衰减区以及地表探地雷达数据中的阴影区（反射损失）相关；(2)在该泥炭地收集的地表探地雷达数据中，在+11 km范围内经常观察到阴影区（表明高含气量）。实验目的是：(1)对从地表到矿物土壤的泥炭岩心剖面的介电常数与气体含量之间的关系进行实验室评估；(2)以水位、水力传导性和时域反射法为支撑，进行跨孔探地雷达和地面探地雷达监测实验，观察生物气向大气释放的速率；(3)一项表面egpr研究，在生物气浓度现场测量的支持下，估计了两个研究良好的北部泥炭地（北美驯鹿沼泽和MN阿加西冰川湖）中储存的生物气体积。重要的里程碑包括：(a)通过介电介电常数测量得出泥炭中气体含量随深度的预测方程，(b)对泥炭地气体释放和膨胀通量的时间模式有了新的认识，以及(c)对泥炭地碳储层中考虑气体空间/深度分布的游离气体含量有了新的估计。更广泛的影响该提案将教育活动、课程开发、社区推广和国际合作纳入应用研究框架。罗格斯-纽瓦克荣誉学院（HC）的荣誉本科生（HUG）研究人员将与一名博士后科学家合作，获得完成四项主要研究任务所需的研究培训。每个HUG将完成一个为期一年的高级研究项目，并发表一篇文章。罗格斯-纽瓦克大学在校园多样性方面排名第一，这为少数民族学生提供了更多的机会。罗格斯-纽瓦克大学地球/环境科学专业的学生经常表达对实地工作经验的兴趣。部分野外工作将由参加新课程的学生进行，该课程名为“应用地球物理学暑期野外营”，是该项目的一部分。社区外展将通过导游、海报和介绍加勒比沼泽的水文、生态和碳循环等方式进行，并由最近开放的2公里长的Orono木板路提供便利，该木板路现在为公众提供通往该沼泽的通道。最后，与欧洲著名泥炭地科学家的合作将引起国际上对我们工作的关注，并提供一个机会，对一个独特的欧洲泥炭沼泽进行比较工作。

0510370 0510545 0510004Slater Glaser ReeveBiogenic gas emission from northern peatlands, by wicking from vascular plants and byepisodic ebullition events, accounts for approximately 7% of the global annual emissionof methane to the atmosphere. This proposal involves experiments to apply groundpenetrating radar (GPR) for (1) estimating the amount of biogenic gas stored in peatlands,(2) determining the spatial distribution of biogenic gas within the peat, and (3)monitoring biogenic gas release to the atmosphere. Data from a large northern peatland inMaine (EAR-0242353) show that (1) higher CH4 and CO2 concentrations correlate withhigh velocity/high attenuation zones in cross-borehole GPR data as well as shadow zones(loss of reflections) in surface GPR data, (2) shadow zones (indicative of high gascontent) are frequently observed in the +11 km of surface GPR data collected in thispeatland. The experimental objectives are: (1) a laboratory evaluation of the relationshipbetween dielectric permittivity and gas content for a profile of peat cores from the surfaceto the mineral soil; (2) a cross-hole GPR and surface GPR monitoring experiment,supported by measurements of water levels, hydraulic conductivity and time domainreflectometry, to observe rates of biogenic gas release to the atmosphere; (3) a surfaceGPR study, supported by in situ measurements of biogenic gas concentration, to estimatethe volume of biogenic gas stored in two well studied northern peatlands (Caribou Bog,ME and Glacial Lake Agassiz, MN). Important milestones include (a) a predictiveequation for gas content estimation in peat as a function of depth from dielectricpermittivity measurements, (b) new insight into the temporal pattern of gas release andebullition flux from peatlands, and (c) new estimates of the free gas content of peatlandcarbon reservoirs accounting for the spatial/depth distribution of the gas.Broader ImpactsThis proposal incorporates educational activities, curriculum development, communityoutreach and international collaboration within an applied research framework. HonorsUnderGraduate (HUG) researchers from the Rutgers-Newark Honors College (HC) willpartner with a postdoctoral scientist to obtain the research training required to completefour of the primary research tasks. Each HUG will complete a yearlong senior project ontheir research and contribute to a publication. The status of Rutgers-Newark as the toprankedNational US University with respect to campus UG diversity facilitates HUGopportunities to minority students. Students in Earth/Environmental Sciences at Rutgers-Newark frequently express interest in fieldwork experiences. Part of the fieldwork will beconducted by students participating in a new class, Summer Field Camp in AppliedGeophysics, developed as part of this project. Community outreach will occur via guidedtours, poster boards and presentations on the hydrology, ecology and carbon cycle inCaribou Bog, facilitated by the recently opened 2 km long Orono boardwalk that nowprovides public access to this bog. Finally, collaboration with a prominent peatlandscientist in Europe will draw international attention to our work and provide anopportunity to conduct comparative work on a unique European peat bog.